Plasma etching is commonly used in the fabrication of transistors and other electronic devices. During plasma etch processes used to form transistor structures, one or more layers of a film stack (e.g., layers of silicon, polysilicon, hafnium dioxide (HfO2), silicon dioxide (SiO2), metal materials, and the like) are typically exposed to etchants comprising at least one halogen-containing gas, such as hydrogen bromide (HBr), chlorine (Cl2), carbon tetrafluoride (CF4), and the like. Such processes cause a halogen-containing residue to build up on the surfaces of the etched features, etch masks, and elsewhere on the substrate.
To remove the residues from the processed substrate, an abatement process may be performed. The abatement process may include heating the processed substrate to a desired temperature while providing one or more process gases, such as ozone, to promote the outgassing of residues from the substrate surface and to abate the outgassed residues. Previously, the abatement process has been performed independently in one or more process chambers. However, the inventors, in working to develop a new process platform where abatement processes run concurrently in a pair of process chambers, have observed that certain conventional process gas delivery systems have configurations that may lead to inaccuracies in the gas delivered to the process chamber when concurrently providing shared process gases to the pair of process chambers.
Therefore, the inventors have provided an improved method and apparatus for providing a gas mixture to a pair of process chambers.